The Atari compendium
By: [Scott Sanders].
Publisher: SDS Pub.
Published: 1993
Place of publication: Long Beach, CA
Language: eng
Subjects: Atari computer -- Programming.
Notes: Includes bibliographical references and index.
"Covers TOS 1.0-5.0" (1.0-4.04 I believe, possibly 4.96, but not 5.x)

online version here:
http://www.fortunecity.com/skyscraper/apple/308/html/toc.htm
pdf version here:
http://dev-docs.atariforge.org/files/The_Atari_Compendium.pdf
Table of contents: title: Introduction to Atari Programming
label: Chapter 1; title: Atari Computer Hardware; title: Atari Computer Software; title: Atari GEM; title: Third-Party System Software; title: Programming Languages; title: Conventions; title: GEMDOS
label: Chapter 2